NOTE: It is possible that a similar crash can occur in Notes, especially with local databases.

Answer

This issue was reported to Quality Engineering as SPR# DJOE69PDXC. The issue no longer occurs in Notes/Domino 6.5.5 and later releases. Starting in Notes/Domino 6.5.5, the usage only returns a single UNID even if it should return a list of UNIDs. While this change in behavior may avoid the crash, it can also cause applications to not function as expected.

To avoid the crash as well as the undesired behavior (specific to 6.5.5 and later), do not use @DBLookup with [RETURNDOCUMENTUNIQUEID]. Instead, create a View column with the formula, @Text(@DocumentUniqueID), and have @DBLookup return that column's data.Note:If you do not want the UNID to appear in the view, create a second hidden view that contains only the key column and the UNID column.

Supporting information: Use of the @DBLookup function with the [RETURNDOCUMENTUNIQUEID] keywords parameter can also cause the Domino server to crash when the function is used in a web application. In a reported case, @DBLookup was used within a hotspot formula in a form design. When a document was created or opened, the Domino server crashed. This issue was reported to Quality Engineering as SPR# CYII633UWJ and was fixed in Notes/Domino 6.5.5. It has not been determined if the fix resulted in the undesired behavior where the function only returned one UNID instead of a list of UNIDs.